Set extra 5 to be the carbon roof, then switch the spoilers to 2-4. Then add the ide flags ext_requi+ext_taxi+ext_strong. Ext_requi cycles through extras 0-4, and ext_taxi cycles through 5-9. If you set both at the same time, you force there to be at least one extra from both groups. Then ext_strong prevents the extras from flying off when you bump something.

ext_gang - spawns all extras simultaneously that are named extra_5 and above

ext_rare - spawning with extras will be rare

ext_requi - extra required, will always spawn with an extra (if model file has them of course)

ext_strong - if this flag is not enabled, the extras will fall off with minor collisions, if enabled, they will not

ext_taxi - will cycle thru extras named extra_5 and above

ext_requi cycles through all extras, unless combined with ext_gang or ext_taxi, in which case it will only cycle through 0-4. If you use it with ext_gang, it will spawn as either ext_requi (for 0-4), or ext_gang, never both.

ext_requi + ext_taxi I already explained above.

And finally, here are a few more that may or may not be useful.

avoidturns - if the car is big, like bus, it won't take sharp turns

bangerexhaustfx - dirty smoke (beater cars)

ext_conv - player will jump into the car since it's a convertible

isvan - (vehicle has van style rear doors)

livery - multiple liveries

noboot - you won't see the car parked at the side of the road with a ped looking inside the trunk/hood.

@ Agonist I don't mean no disrespect, but i test this posted in gtaforums looon looong ago. Extras flags are very inaccurate, some of them completely wrong. Ext_taxi works all extras, just 1st groups differently then 2nd. Ext_conv works extras in very specific way, not just jumping in without opening doors. If he wants roofs working in rain plus different extras I have that done working 100%, but i couldn't use simply whats written there. Also i'm finding new features of each flag all the time. For example just recently, with ext_taxi, emissive on extras will be lit only if they in 1-4.

If they want roofs in rain, plus other no roof extras, for me it works like this. Ext_taxi alone makes 1-4 in random or none and 5-8 in random, but one is always there. 9 never spawns, don't know why. So those two groups work like that simultaneously just with ext_taxi alone. With this you can get things spawned together.

Ext_taxi+ext_conv...Roofs in rain will change some. If you have more then one roof they all have to be 2,3,4. If you only have one roof and you place it on #2, there must be no 3,4 otherwise what ever will be there will cycle in rain as roof, then make empty dummy as extra 1. Ext_conv makes 1 ignored in rain and cycles 2,3,4 always. But in dry it uses 1 too but it keeps always cycling so empty #1 makes no roof in dry. That i just copied from Feltzer, without empty #1 you'll always have roof in dry weather.

Finally 5-8 you do all your other extras, spoilers and those. But since 5-8 makes always one extra, if you want sometimes none of those, you have to make one of them empty too.

Ext_conv will also make front door windows down while no roof. So it's good to attach rear side windows to roof to get perfect flat now side window convertible... All this setup works 100% for me, hopefully it helps you. Sorry for this crazy novel.

LOL, freaking mess. It's still not complete for ext_taxi, just worked on something and found another feature to it. But all explained above works, i do have one setup just like that, it's gonna be in update of modded Rebla.

Anyways ^ those are just little things, thanks goes to all guys making gtaV converts for us.